This study will evaluate the effect of human leukocyte interferon on several stages and types of non-Hodgkin's lymphoma. The initial studies will be done on patients with advanced but objectively measurable disease who have failed other conventional therapy. Then, if results are encouraging, patients with "good" risk and "poor" risk types of histologically and clinical staged disease will be utilized to evaluate, on a controlled basis, the effect of short-term but intensive interferon therapy on disease status and recurrence. This will be done both by contrast with and in concert with conventional therapy. Careful observation of interferon pharmacokinetics, effect of treatment on clinical course and possible side effects will be carried out throughout the trials.